Process and apparatus for insuring the straightness of metal tubes and strips of angle or other form during heat treatment



Jan. 26 1926. 1,570,815

- H-. N. WYLIE PROCESS AND APPARATUS FOR INSURING THE sTRAIGHTNEss OF METAL TUBES, AND STRIPS 0F ANGLE OTHER FORM, DURING HEAT T ATMENT v Fi d June 1, 1925 2 S cs-Sheet 1 1M Ms.

INVENTOR: HAMnJm N. WYLIE 15 l mam v nu ca Q Q v MN A ma @Q %J@ Jan. 26 1926. 1,570,815

H. N. WYLlE PROCESS AND APPARATUS FOR INSURING THE STRAIGHTNESS OF METAL TUBES,

AND STRIPS OF ANGLE OR OTHER FORM, DURING HEAT TREATMENT Filed June 1, 1925 2 Sheets-Sheet 2 S INVENTOIZ.

I I HAMILTON N WYLIE,

' mammumilw r I Ms.

Patented 25,1926.

TAT

HAMILTON NEIL WYLIE,

A 1,570,815 PATENT OFFICE.

01: COVENTRY, ENGLAND.

. PnooE'ss'ANn APPARATUS FOR msUEINe'TnE sTEAIon NEss F METAL TUB S AND i STRIPS OF ANGLE OR OTHER F can DUEI'NG HEAT TREATMENT.

Application filed June 1, 1925. Serial No. 34,110.

To a-llavkom itqnag concern.

,.;-Be .it known that I, HAiwuuroN NEIL IVYLIE, :asubjectof the King otEngland, residingat'Coventry, in the county of Warwicl ,-England,- have invented certain new and useful Improved Process and Apparatus for Insuring the Straightness of Metal Tubes and; Strips oi -Angle or Other Form During Heat Treatment, of which the following is-arspecificationzi Thisiinvention relates to an improved process sand apparatus 1 for insuring the straightness of metal tubes, and strips of angle or-otheriorm, during heat treatment: It 'hasfforitsprincipal object to provide a'simple commercial process which will produce uniform heat treatment of the material, and atflthe same time will straighten it if initially crooked and insure such straightne'ss being'maintained during cooling.

" .7- The manner of carryig out the invention is illustrated in the in whichv =I-Tigure i1 is -a;longitudinal section of a preferred form of apparatus for carrying outthef -in entiorr,

accompanying drawings,

H The tiibes -jstrip's 1 and 2, or the like are arranged horizontally side by side and spacedfap arfl Each end 3 of the strips is elampedfto a bracket 4, preferably of coper, wh1c is rigidly bolted to a concrete 3 bed 5 supportedfon masonry 6 and forming thelower 'sllirface of a muflie .7 or equivalent.

The two brackets-4' are electrically distinct from one another'and are each connected by 'metal s t rips"*8 with electrical conductors "9 v and IOEEo'rmin'g part of the supply "system forfth heating.-current applied to the strip. The her"ends" 11 of the strips are gripped-swamps "12 which are electrically connected together by :a conducting member 133 fTd eaclrofthe'se'clamp'sis attached a yokeionshackle l li and to the yoke is attached' 'a cable 15 which isformed in two parts connected by an insulator 16. Thus it will be seen that the electrical current is confined to the path indicated by the various elements, comprising an anchored clamp 4 for one strip, the strip itself, through the conductor 13 at its end into the adjacent strip, and thence through the other anchored clamp 4 to the main lead.

The cables 15 extend horizontally from the insulators 16 through clearance passages 17 formed in the end walls 18 of the muflie, and from thence pass over guide pulleys 19 for attachment to rods 20 adaptedfto carry removable weights 21 so that any desired load may 'be put upon the strips 1 and 2. A-

manually operable lever 22 is pivoted at .23 to a bracket 24 attached to the end wall of the muffle or the masonary 6 below the guide pulley- 9, and has a' pin-and-slot engagement 2 v the strips may be withdrawn by raising the lever and securing it by means such as a spring detent or a pin 26 adapted to extend through the lever 22 and a hole 27 in the bracket 24.

The mufiie 7 is closed by a lid 28 hinged at 29 along one side of the mufile and provided with an operating handle 30 at its free eggs and a counterpoise 31 at its opposite e ge.

The lower part of the mufile forms a trough into which cooling fluid may be quickly supplied from an adjacent service tank (not shown), a pump also being provided to return the fluid to the tank after the cooling, In the arrangement shown, a channel 32 is provided around the inner edge of the mufile, and the service pipes '33 for the cooling fluid are arranged around this .channel with suitably located inlets and outlets at 34 and 35. A drain36 may also'be provided atone cornerof the mufiie.

, The electrical circuit may include a quickbreak switch, and if preferred tripping means may be provided \at a prearranged temperature of the strip is quickly raised,

and, under theload, it elongates, and at the same time the load straightens the strip.

By this arrangement the extent of such elonmedium, particularly a non-oxidizing gas,

vith the rod 20 so that the loads on distance below the'loading device for the strip. When the current is switched on, the U voltage of supply are determined by the muflie may be provided with means where'-' by it may be filled with an inert gas or gases,

'such as hydrogen, steam, or other non-oxidizing gas. In this way the strip is protected from oxidation while at a high temperature.

It will be understood that the clamps employed for securing the ends of the strips will be suitably shaped to conform to the material and to distribute the stress due to the load uniformly over the cross section of the strip. If preferred, the strip, tube or the like may be flattened for a short distance at its ends and thereby the nature of the clamp is simplified. n this case, if preferred, a bolt may extend through the clamp and the strip and may serve also to secure the electrical conductor at the same time. It is of importance, however, that any holes pierced in the strip for the reception of these bolts should be on the axial line of the strip;

One of the strips may be replaced by a conductor of low resistance when it is desired to economise current or to apply a particularly heavy current to the other strip, or when only one strip is to be treated at a time.

.treatment and straightening of the strip being effectively carried out.

From the foregoing, therefore, it will be seen that the process can be very simply car- --ried out, and that the straightening of the material is effectively accomplished and its cooling under load prevents any risk of distort-ion.

What I claim as my invention and desire to secure by Letters Patent of the United States is 1. A process for heat treating and for insuring the straightnessof metal tubes and strips of angle or other form during heat treatment, consisting in first subjecting the tube, strip or the like to a predetermined tensile load, and, while so loaded, heating it by the passage through it of an electric current which is cut off when the required temperature of the material is attained and the desired straightening has been effected, after which, when the strip has cooled sufliciently, the load is'removed, substantially as and for the purpose described.

2. A process for heat treating and for insuring the straightness of metal tubes and strips of angle or other form during heat treatment, as claimed in claim 1, in which In an alternative arrangement of appa-Fthe tube or strip is enclosed in a mufile or ratus, the tube or strlp may be suspended at one end and loaded at the other to hang vertically. Preferably, however, a pair oftubes or strips are "arranged side by side and spaced apart, as in the apparatus above described, the electrical supply connections then being made either at the upper or the lower ends of the stri s as may be most convenient. A cable and winding drum with appropriate insulating means may-be employed for hoisting the clamp or clamps used to suspend the strip.

In carrying out the process, it is to be understood that the extent of the heating, the intensity of the loading of the material, and the allowable stretch thereof during the straightening, as well as the nature and rapidity of the cooling means, are each determined in accordance with the requirements of the material undergoing treatment. In the same way, the current applied and the quantity of material to be heated and also its specific heat and the time allowed for its attainment of the desired temperature.

It has been found practicable so to regulate the current that within five seconds of switching it on the material becomes just red hot, attains its full red heat in twenty seconds, and after being subjected. to this condition for ten seconds the current is equivalent adapted to containan inert gas and provided with means'for quenching the tube or strip by means of a cooling fluid, substantially as and for the purpose described.

3. A process for heat treating and forinsuring the straightness of metal tubes and strips of angle or other form during heat treatment, as claimed in claim 1, in which the electrical circuit includes a quick-break switch with tripping means adapted to be the load-applying mechanism during the straightening of the strip, substantially as and for the purpose described.

4. A method of treating metal elements which includes the steps of subjecting said elements to heat while under tension, cutting oii the application heat thereto while under tension, and retaining the element under tension until it has cooled to a predetermined degree. 5.A method of treating metal elements which includes the steps "of subjecting said element to heat while under tension andsuractuated by a prearranged movement of 

